PALEOGEOGRAPHY OF THE SARTAN GLACIATION OF THE PATOMSKY AND NORTH-BAIKAL HIGHLANDS

2020 ◽  
Vol 26 (8) ◽  
pp. 16-30
Author(s):  
F. Enikeev ◽  
Keyword(s):  
Lower Boundary ◽  
Gold Deposits ◽  
Valley Bottom ◽  
Mountain Valley ◽  
The North ◽  
Ice Surface ◽  
Time Period ◽  
Direction Of Movement ◽  
The Difference ◽  
River Valleys

The article presents the results of the reconstruction of the spatial boundaries and parameters of glaciers for the isolated mountain structures of the Patomsky and North Baikal uplands in the era of the Last Glaciation (MIS 2) with the construction of a paleogeographic map. The object of this study is the dynamics of exogenous processes during the development of the permafrost zone in Eastern Siberia. The subject of research is the glacial relief forms of the Late Neopleistocene of the Patomsky and North Baikal uplands. The comparative, descriptive, cartographic research methods, methods of observation and actualism have been used. Based on the interpretation of aerial and satellite images, the identification of typomorphic glaciers with the maximum number of preserved destructive and accumulative glaciogenic forms, a depression of the snow boundary was established, which at that time was at the level of 2000…2100 m. The features of the lower boundary deformations of the chionosphere were revealed. Its deepest minimum is noted on the northwestern edge of the considered territory. The greatest decrease in relation to the paleoclimatic snow boundary, which extended to an altitude of 1600…1700 m, was 600…700 m. The positive extremum was confined to the central part of the Patom upland and exceeded the paleoclimatic snow line by 50…100 m. Anomalous extremes at that time period are due to global climatic, regional orographic and local (slope exposure) causes. It has been determined that in terms of morphology, glaciation of the territories under consideration is mountain-valley and reticulate with several sections of mountain-cover, confined to the flattened surfaces of the summit belt of mountain structures. According to the difference between the ice surface isolines and the valley bottom in the cross section, the thickness of the glacier was specified, and could reach 400…600 m. When searching for alluvial occurrences and gold deposits, as well as when sampling placer flows and secondary geochemical halos, it is recommended to orient prospecting in the direction of movement of ice masses. The new paleogeographic data obtained will increase the possibilities of more efficient mapping of Quaternary sediments within the North Baikal and Patom uplands and the identification of specific sections of river valleys in this area, favourable for placer formation

scholarly journals Pleistocene horses (genus Equus) in the central Balkans

2003 ◽  
pp. 55-75 ◽  
Author(s):  
Ann Forsten ◽  
Vesna Dimitrijevic
Keyword(s):  
Late Pleistocene ◽  
River Valley ◽  
Middle Pleistocene ◽  
Mountainous Area ◽  
Migration Routes ◽  
Northern Greece ◽  
The North ◽  
Time Period ◽  
Morava River ◽  
River Valleys

A review of the fossil horses of the genus Equus from the central Balkans, a mountainous area comprising Serbia and Montenegro, is presented in this paper. The time period covered by the finds is from the late Early to and including the Late Pleistocene, but the record is not complete: the dated finds are Late Pleistocene in age, while Early and Middle Pleistocene are poorly represented. The horses found resemble those from neighbouring countries from the same time period, probably showing the importance of river valleys as migration routes. The Morava River valley runs in a roughly south-to-north direction, connecting, via the Danube and Tisa River valleys the Hungarian Pannonian Plain in the north with northern Greece in the south, via the Vardar River valley in Macedonia. In Pleistocene, large mammals, including horses, probably used this route for dispersal.

Meadows of the North-Eastern Altai

2002 ◽  
pp. 22-31 ◽  
Author(s):  
T. V. Maltseva ◽  
N. I. Makunina
Keyword(s):  
Coniferous Forest ◽  
Wet Meadows ◽  
Abies Sibirica ◽  
Dark Coniferous Forest ◽  
Hay Meadows ◽  
The North ◽  
North Eastern ◽  
Humid Area ◽  
River Valleys

The North-Eastern Altai is an ultra-humid area with climax vegetation represented by tall-herb fir (Abies sibirica) dark-coniferous forest. Its meadows belong to the class Molinio-Arrhenatheretea. The typical asso­ciation Aegopodio podagrariae—Dactyletum glomeratae originates in the watershed clearings after climax forests whereas ass. Hyperici perforati—Agrostietum giganteaereplaces the previous one under mowing and grazing. The Molinietalia wet meadows are widespread in the river valleys. The meadows of ass. Cirsio heterophylli—Calama­grostietum langsdorffii occur on wet soils in small depressions and along floodplain mire margins, and ass. Ca­rici ovalis—Deschampsietum cespitosae comprises typical floodplain hay-meadows on moist, nutrient-rich soils.

scholarly journals A Stepwise GIS Approach for the Delineation of River Valley Bottom within Drainage Basins Using a Cost Distance Accumulation Analysis

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 827
Author(s):  
Gasper L. Sechu ◽  
Bertel Nilsson ◽  
Bo V. Iversen ◽  
Mette B. Greve ◽  
Christen D. Børgesen ◽  
...  
Keyword(s):  
Spatial Data ◽  
Nutrient Loading ◽  
Drainage Basin ◽  
River Valley ◽  
Management Tool ◽  
Drainage Basins ◽  
Valley Bottom ◽  
Management Actions ◽  
Cost Distance ◽  
River Valleys

River valley bottoms have hydrological, geomorphological, and ecological importance and are buffers for protecting the river from upland nutrient loading coming from agriculture and other sources. They are relatively flat, low-lying areas of the terrain that are adjacent to the river and bound by increasing slopes at the transition to the uplands. These areas have under natural conditions, a groundwater table close to the soil surface. The objective of this paper is to present a stepwise GIS approach for the delineation of river valley bottom within drainage basins and use it to perform a national delineation. We developed a tool that applies a concept called cost distance accumulation with spatial data inputs consisting a river network and slope derived from a digital elevation model. We then used wetlands adjacent to rivers as a guide finding the river valley bottom boundary from the cost distance accumulation. We present results from our tool for the whole country of Denmark carrying out a validation within three selected areas. The results reveal that the tool visually performs well and delineates both confined and unconfined river valleys within the same drainage basin. We use the most common forms of wetlands (meadow and marsh) in Denmark’s river valleys known as Groundwater Dependent Ecosystems (GDE) to validate our river valley bottom delineated areas. Our delineation picks about half to two-thirds of these GDE. However, we expected this since farmers have reclaimed Denmark’s low-lying areas during the last 200 years before the first map of GDE was created. Our tool can be used as a management tool, since it can delineate an area that has been the focus of management actions to protect waterways from upland nutrient pollution.

scholarly journals Torrential Flood Water Management: Rainwater Harvesting through Relation Based Dam Suitability Analysis and Quantification of Erosion Potential

2021 ◽  
Vol 10 (1) ◽  
pp. 27
Author(s):  
Bilal Ahmad Munir ◽  
Sajid Rashid Ahmad ◽  
Raja Rehan
Keyword(s):  
Sediment Yield ◽  
Soil Loss ◽  
Rainwater Harvesting ◽  
Suitability Analysis ◽  
Valley Bottom ◽  
The North ◽  
Roughness Index ◽  
Dam Site ◽  
Very High

In this study, a relation-based dam suitability analysis (RDSA) technique is developed to identify the most suitable sites for dams. The methodology focused on a group of the most important parameters/indicators (stream order, terrain roughness index, slope, multiresolution valley bottom flatness index, closed depression, valley depth, and downslope gradient difference) and their relation to the dam wall and reservoir suitability. Quantitative assessment results in an elevation-area-capacity (EAC) curve substantiating the capacity determination of selected sites. The methodology also incorporates the estimation of soil erosion (SE) using the Revised Universal Soil Loss Equation (RUSLE) model and sediment yield at the selected dam sites. The RDSA technique identifies two suitable dam sites (A and B) with a maximum collective capacity of approximately 1202 million m3. The RDSA technique was validated with the existing dam, Gomal-Zam, in the north of Sanghar catchment, where RDSA classified the Gomal-Zam Dam in a very high suitability class. The SE estimates show an average of 75 t-ha−1y−1 of soil loss occurs in the study area. The result shows approximately 298,073 and 318,000 tons of annual average sediment yield (SY) will feed the dam A and B respectively. The SE-based sediment yield substantiates the approximate life of Dam-A and Dam-B to be 87 and 90 years, respectively. The approach is dynamic and can be applied for any other location globally for dam site selection and SE estimation.

scholarly journals Large numbers of vertebrates began rapid population decline in the late 19th century

2016 ◽  
Vol 113 (49) ◽  
pp. 14079-14084 ◽  
Author(s):  
Haipeng Li ◽  
Jinggong Xiang-Yu ◽  
Guangyi Dai ◽  
Zhili Gu ◽  
Chen Ming ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Size ◽  
Threatened Species ◽  
Driving Forces ◽  
Population Decline ◽  
Cumulative Effect ◽  
Extinction Time ◽  
Time Period ◽  
Large Numbers ◽  
The Difference

Accelerated losses of biodiversity are a hallmark of the current era. Large declines of population size have been widely observed and currently 22,176 species are threatened by extinction. The time at which a threatened species began rapid population decline (RPD) and the rate of RPD provide important clues about the driving forces of population decline and anticipated extinction time. However, these parameters remain unknown for the vast majority of threatened species. Here we analyzed the genetic diversity data of nuclear and mitochondrial loci of 2,764 vertebrate species and found that the mean genetic diversity is lower in threatened species than in related nonthreatened species. Our coalescence-based modeling suggests that in many threatened species the RPD began ∼123 y ago (a 95% confidence interval of 20–260 y). This estimated date coincides with widespread industrialization and a profound change in global living ecosystems over the past two centuries. On average the population size declined by ∼25% every 10 y in a threatened species, and the population size was reduced to ∼5% of its ancestral size. Moreover, the ancestral size of threatened species was, on average, ∼22% smaller than that of nonthreatened species. Because the time period of RPD is short, the cumulative effect of RPD on genetic diversity is still not strong, so that the smaller ancestral size of threatened species may be the major cause of their reduced genetic diversity; RPD explains 24.1–37.5% of the difference in genetic diversity between threatened and nonthreatened species.

A Reinterpretation of the Microlithic Industries of Wales

1963 ◽  
Vol 29 ◽  
pp. 99-132 ◽  
Author(s):  
G. J. Wainwright
Keyword(s):  
Short Distance ◽  
The South ◽  
The West ◽  
The North ◽  
South Wales ◽  
North Wales ◽  
River Valleys

The distribution of Mesolithic sites in Wales is controlled to a great extent by the terrain, for physiographically, Wales is a highland block defined on three sides by the sea and for the greater part of the fourth side by a sharp break of slope. Geologically the Principality is composed almost entirely of Palaeozoic rocks, of which the 600-foot contour encloses more than three quarters of the total area. There are extensive regions above 1,500 feet and 2,000 feet and in the north the peaks of Snowdonia and Cader Idris rise to 3,560 feet and 2,929 feet respectively. Indeed North Wales consists of an inhospitable highland massif, skirted by a lowland plateau and cut deeply by river valleys, providing only limited areas for settlement. The hills and mountains of Snowdonia with their extension at lower altitudes into the Lleyn Peninsula, and the ranges of Moelwyn, Manod Mawr, Arenig Fach and Cader Idris, are discouraging obstacles to penetration, save for a short distance along the river valleys. To the east of these peaks are extensive tracts of upland plateau dissected by rivers, bounded on the west by the vale of the river Conway and cleft by the Vale of Clwyd. To the east of this valley lies the Clwydian Range and further again to the east these uplands descend with milder contours to the Cheshire and Shropshire plains.To the south the district merges into the uplands of Central Wales, which are continuous until they are replaced by the lowland belt of South Wales.

Gold deposits of the northern margin of the North China Craton: multiple late Paleozoic–Mesozoic mineralizing events

2002 ◽  
Vol 37 (3) ◽  
pp. 326-351 ◽  
Author(s):  
Craig J. Hart ◽  
Richard J. Goldfarb ◽  
Yumin Qiu ◽  
Lawrence Snee ◽  
Lance D. Miller ◽  
...  
Keyword(s):  
North China Craton ◽  
North China ◽  
Gold Deposits ◽  
Late Paleozoic ◽  
Northern Margin ◽  
The North

scholarly journals Barotropic Regeneration of Upper-Level Synoptic Disturbances in Different Configurations of the Zonal Weather Regime

2008 ◽  
Vol 65 (10) ◽  
pp. 3159-3178 ◽  
Author(s):  
Gwendal Rivière
Keyword(s):  
Large Scale ◽  
Deformation Field ◽  
Regeneration Process ◽  
Barotropic Model ◽  
Weather Regime ◽  
The North ◽  
The Difference ◽  
Upper Level ◽  
Composite Maps ◽  
Large Scale Flow

Barotropic dynamics of upper-tropospheric midlatitude disturbances evolving in different configurations of the zonal weather regime (i.e., in different zonal-like large-scale flows) were studied using observational analyses and barotropic model experiments. The contraction stage of upper-level disturbances that follows their elongation stage leads to an increase of eddy kinetic energy that is called the barotropic regeneration process in this text. This barotropic mechanism is studied through notions of barotropic critical regions (BtCRs) and effective deformation that have been introduced in a previous paper. The effective deformation field is equal to the difference between the square of the large-scale deformation magnitude and the square of the large-scale vorticity. Regions where the effective deformation is positive correspond to regions where the large-scale flow tends to strongly stretch synoptic disturbances. A BtCR is an area separating two large-scale regions of positive effective deformation, one located upstream and on the south side of the jet and the other downstream and on the north side. Such a region presents a discontinuity in the orientation of the dilatation axes and is a potential area where the barotropic regeneration process may occur. Winter days presenting a zonal weather regime in the 40-yr ECMWF Re-Analysis dataset are decomposed, via a partitioning algorithm, into different configurations of the effective deformation field at 300 hPa. A six-cluster partition is obtained. Composite maps of the barotropic generation rate for each cluster exhibit a succession of negative and positive values on both sides of the BtCRs. It confirms statistically that the barotropic regeneration mechanism occurs preferentially about BtCRs. Numerical experiments using a forced barotropic model on the sphere are performed. Each experiment consists of adding a synoptic-scale perturbation to one of the zonal-like jet configurations found in observations, which is kept fixed with time. The combined effects of the effective deformation and nonlinearities are shown to be crucial to reproduce the barotropic regeneration process about BtCRs.

United Front: Partisans of the Leningrad Region and their connections with the Central Asian Soviet Republics

2021 ◽  
Vol 2021 (02) ◽  
pp. 214-225
Author(s):  
Sergey Kulik ◽  
Аnatoliy Kashevarov ◽  
Zamira Ishankhodjaeva
Keyword(s):  
World War Ii ◽  
Weather Conditions ◽  
Leningrad Region ◽  
World War ◽  
North West ◽  
The North ◽  
Occupied Territory ◽  
Central Asian ◽  
The Difference ◽  
Almost All

During World War II, representatives of almost all the Soviet Republics fought in partisan detachments in the occupied territory of the Leningrad Region. Among them were many representatives of the Central Asian republics: Kazakhstan, Kyrgyzstan and Uzbekistan. Many Leningrad citizens, including relatives of partisans, had been evacuated to Central Asia by that time. However, representatives of Asian workers’ collectives came to meet with the partisans. The huge distance, the difference in cultures and even completely different weather conditions did not become an obstacle to those patriots-Turkestanis who joined the resistance forces in the North-West of Russia.

Examining the impacts of Great Lakes’ temperature perturbations on simulated precipitation in the northeastern United States

2021 ◽  
Author(s):  
Janel Hanrahan ◽  
Jessica Langlois ◽  
Lauren Cornell ◽  
Huanping Huang ◽  
Jonathan Winter ◽  
...  
Keyword(s):  
Great Lakes ◽  
New England ◽  
General Circulation ◽  
Lower Boundary ◽  
Historical Period ◽  
Spatial And Temporal Variability ◽  
Lake Surface ◽  
The North ◽  
Surface Temperatures ◽  
Simulated Precipitation

AbstractMost inland water bodies are not resolved by General Circulation Models, requiring that lake surface temperatures be estimated. Given the large spatial and temporal variability of the North American Great Lakes’ surface temperatures, such estimations can introduce errors when used as lower boundary conditions for dynamical downscaling. Lake surface temperatures (LSTs) influence moisture and heat fluxes, thus impacting precipitation within the immediate region and potentially in regions downwind of the lakes. For the present study, the Advanced Research Weather Research and Forecasting Model (WRF-ARW) was used to simulate precipitation over six New England states during a five-year historical period. The model simulation was repeated with perturbed LSTs, ranging from 10°C below to 10°C above baseline values obtained from reanalysis data, to determine whether the inclusion of erroneous LST values impact simulated precipitation and synoptic-scale features. Results show that simulated precipitation in New England is statistically correlated with LST perturbations, but this region falls on a wet-dry line of a larger bimodal distribution. Wetter conditions occur to the north and drier conditions to the south with increasing LSTs, particularly during the warm season. The precipitation differences coincide with large-scale anomalous temperature, pressure, and moisture patterns. Care must therefore be taken to ensure reasonably accurate Great Lakes’ surface temperatures when simulating precipitation, especially in southeastern Canada, Maine, and the Mid-Atlantic region.

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